There is an ever increasing demand for communications infrastructure that can support inexpensive, high-speed communications to every residential and business address that desires it. As one example, the use of the Internet for commerce, education, entertainment, communications, and many other purposes is quickly developing. There is likewise an increasing interest in providing entertainment and other services to residential and business customers that require moving large amounts of data very quickly, i.e. that have high band-width requirements, such as video-on-demand, high fidelity audio, high definition television, computer software, documents, medical X-ray charts, digital photography, and the like.
It is well known to implement the needed communications infrastructure by interconnecting communications nodes using wires and cables. However, cabling is expensive and time-consuming to deploy, and it has not been able to fulfill the expanding demand for high-speed communications services.
Wireless communications systems provide a relatively low cost alternative to wire-based communications networks, and they are quicker to deploy. One known wireless network architecture is the wireless local network having one or more base stations or server nodes distributed throughout a region of system users. Each system user has wireless equipment for communicating bi-directionally with a server node. This type of wireless network is sometimes referred to as a “last mile” network, because information content can be distributed from a high bandwidth source by cable to a server node that is in the neighborhood of the system user and then distributed the “last mile” via a wireless link between the server node and the system user's equipment.
The known wireless local networks are subject to various types of impairments of the communications channel(s). Some impairments are pre-existing, e.g. geographical features such as mountains, high buildings, etc. Other impairments develop after establishment of the wireless local network, e.g. foliage growth, new building construction, etc. Still other impairments are transitory, e.g. power disruptions; maintenance down-time; weather conditions such as fog, heavy rain, dust storms, lightning storms, solar storms (to the extent their effect may be localized by line-of-sight conditions); and so forth.
Accordingly, there is a significant need for systems and methods that can mitigate signal path impairments in a wireless communications system.